This word means to have sex after a long period of time has gone by since one has engaged in sexual intercourse. This is normally used for males referring to the wetness of a vagina would be quenching the thirst or "Ending the Drought" of their penis, but this could also go for women too, as they would be ending the drought after becoming extremely aroused after a long duration without sexual interaction.

Male #1: Hey man, I see you've been talkin' to Stacy, what's goin' on with that?
Male #2: Oh yeah, I was goin' to End the Drought last night, but she was on her period.
Male #1: DAAAAAYUUUUUMMM.....